Bittrex and Binance are indefinitely disabled.
Poloniex is open but is never safe to use. #jsunthing
Ionomy is also open but will take time to create an account.
But don't worry, there's one last option for your steem to converted/sold into/for hive, and that's with the help of Hive-engine.
In this 3-min video that will guide you on how to convert your tokens, you'll just have to visit a single site without directing yourself into other websites. But you need to have the following wallet apps for your operation.
Every operation takes a few seconds and delay in reflecting into your wallet balance. Just do some page refresh every now and then.
I hope it helps.